642860111 has 2 divisors, whose sum is σ = 642860112. Its totient is φ = 642860110.

The previous prime is 642860093. The next prime is 642860123. The reversal of 642860111 is 111068246.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642860111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642860011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321430055 + 321430056.

It is an arithmetic number, because the mean of its divisors is an integer number (321430056).

Almost surely, 2^642860111 is an apocalyptic number.

642860111 is a deficient number, since it is larger than the sum of its proper divisors (1).

642860111 is an equidigital number, since it uses as much as digits as its factorization.

642860111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 642860111 is about 25354.6861743544. The cubic root of 642860111 is about 863.0557022678.

The spelling of 642860111 in words is "six hundred forty-two million, eight hundred sixty thousand, one hundred eleven".